New cogeneration engine could help Medford meet tougher pollution rules

Thursday

Jul 10, 2014 at 2:00 AM

A new cogeneration engine at the regional water-reclamation facility near Central Point turns methane into enough electricity to run the plant, and it is likely to help the city of Medford skate through a new, stricter set of air-pollution rules.

By MARK FREEMAN

A new cogeneration engine at the regional water-reclamation facility near Central Point turns methane into enough electricity to run the plant, and it is likely to help the city of Medford skate through a new, stricter set of air-pollution rules.

The nearly $4 million engine burns clean enough that the facility will meet eight ongoing air-pollution standards as well as two new ones — for fine particulate matter and greenhouse gases, city officials said.

The old engine was notorious for expensive repairs, and it regularly caused shutdowns at the plant off Kirkland Road along the Rogue River.

"With this new engine, we are not going to exceed anything," said Cory Crebbin, Medford's public works director.

"We'll never be down because of a discharge again. Those levels are not going to be an issue."

Medford is in the midst of getting a renewal of its air-quality permit from the state Department of Environmental Quality to operate the facility, which is formally known as the Vernon Thorpe Regional Water Reclamation Facility.

The DEQ has proposed a five-year renewal of its existing air-quality permit, which was issued in November 2008. Written comments on the proposal will be accepted by the DEQ through July 23.

Since the facility's last permit renewal, fine particulate matter known as PM2.5 and greenhouse gases have been deemed regulated pollutants by the federal Environmental Protection Agency, so they were added to the new draft permit, said Wayne Kauzlarich, a natural resources specialist for the DEQ who is working on the permit.

PM2.5 is finely divided solid or liquid materials with a diameter of 2.5 micrometers or less that are emitted into the air.

The current permit regulated overall particulate matter and small particulate matter PM10, which is commonly found in emissions such as wood smoke. The current permit allows the plant to emit up to 14 tons per year of particulate matter and 4.5 tons of PM10, with both levels rolled over into the new draft permit.

The draft permit would allow the emission of 74,000 tons per year of greenhouse gases, according to the agency.

Greenhouse gases include carbon dioxide and methane.

The methane is a byproduct of the sewage digesters at the plant that treat flows from the cities of Medford, Central Point, Jacksonville, Phoenix, Talent, Eagle Point and unincorporated areas of Jackson County.

To get rid of the methane, the facility has burned it to generate electricity for more than two decades. The system is not designed to send electricity to the power grid, so it is used to power and heat the facility, Crebbin said.

The draft permit covers the engine, which has been in operation for about a year, as well as a backup generator, a boiler and a gas flare used to burn excess methane when not used for electricity production, Crebbins said.

The DEQ rates the facility as one that does not have the potential to be a major source of hazardous air pollutants, according to permit language.

The city's existing air-quality permit was originally scheduled to expire in November 2013. However, according to DEQ rules, the existing permit remains in effect until the proposed permit is issued because the city submitted a timely and complete application for renewal, Kauzlarich said.

Thorpe was the city's public works director in the 1960s when the plant was commissioned.